title: Cost-effectiveness of preoperative imaging for appendicitis after indeterminate ultrasonography in the second or third trimester of pregnancy.
abstract: OBJECTIVE
  To assess the cost-effectiveness of diagnostic laparoscopy, computed tomography (CT), and magnetic resonance imaging (MRI) after indeterminate ultrasonography in pregnant women with suspected appendicitis.
  
  
  METHODS
  A decision-analytic model was developed to simulate appendicitis during pregnancy taking into consideration the health outcomes for both the pregnant women and developing fetuses. Strategies included diagnostic laparoscopy, CT, and MRI. Outcomes included positive appendectomy, negative appendectomy, maternal perioperative complications, preterm delivery, fetal loss, childhood cancer, lifetime costs, discounted life expectancy, and incremental cost-effectiveness ratios.
  
  
  RESULTS
  Magnetic resonance imaging is the most cost-effective strategy, costing $6,767 per quality-adjusted life-year gained relative to CT, well below the generally accepted $50,000 per quality-adjusted life-year threshold. In a setting where MRI is unavailable, CT is cost-effective even when considering the increased risk of radiation-associated childhood cancer ($560 per quality-adjusted life-year gained relative to diagnostic laparoscopy). Unless the negative appendectomy rate is less than 1%, imaging of any type is more cost-effective than proceeding directly to diagnostic laparoscopy.
  
  
  CONCLUSIONS
  Depending on imaging costs and resource availability, both CT and MRI are potentially cost-effective. The risk of radiation-associated childhood cancer from CT has little effect on population-level outcomes or cost-effectiveness but is a concern for individual patients. For pregnant women with suspected appendicitis, an extremely high level of clinical diagnostic certainty must be reached before proceeding to operation without preoperative imaging.
authors.affiliation: Center for Health Policy and Center for Primary Care and Outcomes Research, Department of Medicine, and the Department of Surgery, Stanford University, Stanford, and the Veterans Affairs Palo Alto Health Care System, Palo Alto, California.
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Kastenberg
authors.forename: Michael P
authors.initials: MP
authors.lastname: Hurley
authors.forename: Anna
authors.initials: A
authors.lastname: Luan
authors.forename: Vidya
authors.initials: V
authors.lastname: Vasu-Devan
authors.forename: David A
authors.initials: DA
authors.lastname: Spain
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Owens
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Goldhaber-Fiebert
mesh_terms: D000328:Adult; D001064:Appendicitis / Q000175:diagnosis*; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D010535:Laparoscopy; D008279:Magnetic Resonance Imaging / Q000191:economics*; D009381:Neoplasms, Radiation-Induced / Q000191:economics / Q000209:etiology*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D011262:Pregnancy Trimester, Second; D011263:Pregnancy Trimester, Third; D057234:Preoperative Period; D014057:Tomography, X-Ray Computed / Q000009:adverse effects* / Q000191:economics; D016216:Ultrasonography, Prenatal